Apparatus for cleaning a basic oxygen furnace converter



Aug. 15, 1967 R. c. KINZLER APPARATUS FOR CLEANING A BASIC OXYGEN FURNACE CONVERTER Filed Oct. 16, 1964 N QFR M WPA INVENTOR. PA YMOND C. K/NZLER United States Patent 3,335,445 APPARATUS FOR CLEANING A BASIC OXYGEN FURNACE CONVERTER Raymond C. Kinzler, Carnegie, Pa., assignor to Koppers Company, Inc., a corporation of Delaware Filed Oct. 16, 1964, Ser. No. 404,255 7 Claims. (Cl. 93)

This invention relates to apparatus for cleaning the region adjacent the lip or mouth of a 'basic oxygen furnace converter.

The basic oxygen steel-making process involves blowing a stream of oxygen onto or into a bath of molten pig iron in a furnace vessel or converter to burn impurities from the iron to produce steel. The oxygen flows through a lance which is lowered into the vessel or converter from an elevated position. The reaction of the oxygen with the molten metal occurs almost immediately. After the oxygen blow period, the lance is removed and the furnace is tilted and teemed in the usual manner.

The reaction of the oxygen with the molten metal is sometimes so violent that hot metal is ejected from the vessel and some of the metal, slag, and other ingredients accumulate on the lip or edge of the mouth of the basic oxygen furnace converter. Metal and slag also accumulate on the mouth of the converter during teeming. After a time, the accumulation of such matter becomes excessive and, unless removed, it interferes with the steel-making operation of the basic oxygen furnace.

The present invention provides an apparatus for quickly removing the bothersome accumulated matter from the basic oxygen furnace.

In the present invention, a mobile unit or car is movable relative to a basic oxygen furnace converter, and carries a bar with scraper teeth extending above the upper edge of the bar so that when the vessel is inverted and oscillated about its trunnion axis, the teeth engage and remove the accumulated matter from adjacent the mouth of the converter.

For a further understanding of the present invention and for advantages and features thereof, reference may be made to the following description taken in conjunction with the accompanying drawing forming a part of this application in which:

FIG. 1 is a side elevational view of a furnace cleaning apparatus in accordance with the present invention;

FIG. 2 is an end view of the apparatus taken along line II-II of FIG. 1, with a portion of the structure omitted for clarification purposes; and

FIG. 3 is a plan view of the apparatus taken along line III-III of FIG. 1.

While not shown in the drawings, it is well-known in the art that the basic oxygen furnace vessel has generally a cylindrical main body portion which is closed at one end and a frusto-conical upper body portion terminating in a mouth that is smaller in diameter than the main body portion. The furnace vessel is lined with refractory and has at least one tapping or pouring opening through which the molten steel is poured.

The furnace vessel is customarily mounted upon a pair of trunnions which are fixed to the shell of the vessel and which determine a horizontal axis about which the furnace vessel is rotatable and oscillatable.

FIG. 1 illustrates a furnace cleaning apparatus 11, positioned beneath the basic oxygen furnace vessel or converter 13, which has been rotated to an inverted position for cleaning.

The furnace cleaning apparatus 11 includes generally a mobile unit or car 15 and a scraper device 17, pivotally mounted on the car 15.

The car 15 comprises a rectangular box beam type frame 19 which is preferably open in the central portion.

Frame 19 is pivotally connected by pivot pins 21 to four sets of double wheels 23 which cooperate with and ride upon rails 25 fixed to suitable supporting structure. Rails 25 maybe the rails that are used to support other equipment associated with the furnace, such as the teeming ladle car and the slag transfer car (not shown).

The scraper device 17 is pivotally and resiliently mounted on the car frame 19 so that the resultant of the forces acting on the car is transmitted into the car and is directed at an effective location between the supporting wheels or end reactions of the car. Thus, the car will not overturn when the scraper device is being used in the manner described hereinafter.

To mount the scraper device to the car there is provided at one end of the car frame 19 a pair of angle type brackets 27, 29. These brackets are secured, as by bolts 30, to the frame 19, and support a transversely extending pivot shaft 31 that is journaled in the upstanding legs of the brackets 27, 29. A plurality of longitudinally extending vertical plate members 33 are fixed, as by welding, to the pivot shaft 31, and they are maintained in a c0nvenient spaced apart relation by a pair of diaphragm plate members 35, 37, which may also be fixed as by welding to the vertical plates 33, about where shown in FIG. 1. The vertical plates 33, being effectively joined together by the plate members 35, 37, cooperate as an arm-like structure pivotable about the shaft 31.

The opposite end of the arm-like structure 33 is fixed, as by welding, to a transversely extending upper bearing bar 39, which cooperates with a plurality of spaced apart springs 41. The springs 41 bear against the upper hearing bar 39 at one end, and against a lower bearing bar 43 at the other end, which is fixed to the car frame 19 and which extends transversely thereacross.

During the scraping operation, to be described hereinafter, considerable metal, dirt, and slag material, which is removed from the mouth region of the furnace vessel, would accumulate on the coil springs 41 to such an extent that such material might impair the effectiveness of the springs unless they are protected in some appropriate manner. To this end, there is provided a pair of depending spaced apart upper shield plates 45a, 45b which are secured to the upper bearing bar 39. A cooperating pair of spaced apart upstanding lower shield plates 47a, 47b are secured to the lower bearing bar 43. These upper and lower shield plates 45, 47 overlap, as shown in FIG. 1, and prevent slag, metal, and dirt from accumulating on the springs 41.

It is to be noted that the upper depending shield plate 45b is angularly disposed with respect to the other upper shield plate 45a. Such an angular arrangement of the plate 45b efiectively provides clearance with the cooperating bottom plate 47b when the arm-like structure 33 pivots about the shaft 31.

On the top surface of the upper bearing bar 39, there are a plurality of spaced apart bearing plates 49, which engage the under surfaces of inverted angle-shaped stop members 51. Each stop member 51 is fixed in a vertical position to the frame 19 as by Welding, but, of course, the stop members may be bolted to the frame or secured thereto in any other suitable manner.

The upper edges of the vertical plates forming the arm-like structure 33 are respectively notched to receive a transversely extending scraper support bar 53, on which are mounted a plurality of spaced apart scraper teeth 55. The support bar 53 may be secured to the plates 33 as by welding, or fixed thereto in any appropriate manner. The scraper bar 53 is positioned so that the teeth 55 lie in a plane forming an angle advantageously of about with the plane of the top of the car 15. The scraper teeth 55 have a generally rectangular shape and each is conveniently fixed to the support bar by means of bolts 57, about as indicated in FIG. 1. It will be noticed by referring to FIG. 2, that the upper edge of the scraper support bar 53 has an arcuate shape, with the center of curvature thereof above the bar. Likewise, it will be noticed that the scraper teeth 55 are so positioned on the bar 53 that their upper edges touch an are which is substantially parallel to the upper edge of the support bar 53. The scraper teeth located adjacent to the ends of the support bar 53 are conveniently slightly wider than the intermediary teeth, and thus they provide additional contact with the rim of the vessel 13, as described hereinafter.

The scraper bar 53 has, preferably, an arcuate upper edge for the reason that all of the teeth 55 have, then, substantially the same cantilever operative length. It is generally recognized that the scraper teeth should touch an are having, as shown in FIG. 2, its center of curvature above the teeth. Therefore, in order to maintain substantially the same cantilever operative length for all teeth, the upper edge of the scraper bar should be substantially parallel to the arc touching all of the teeth.

FIG. 1 also illustrates a rubble chute 59 which is fixed to the arm-like structure 33, as by welding or in any other suitable manner, and which extends downwardly and outwardly, at the front end of the apparatus 11. In the embodiment illustrated herein, the rubble chute 59 has a generally planar bottom 61 and vertical sides 63. It is preferably wider at the upper end than at the bottom, but of course, the chute 59 may have any other desirable form.

When slag, metal, and other depository material has accumulated adjacent the mouth region of the oxygen converter 13, and it is determined that it should be cleaned, the vessel is inverted by rotating it about its trunnion axis (not shown), and the car 15 is moved into an operative position beneath the vessel, about where shown in FIG. 1.

The furnace cleaning car 15 may be powered, or motorized with its own braking system, if preferred. But, in the embodiment shown, it is conveniently coupled to another mobile car mentioned previously such as either the ladle teeming car or the slag transfer car. Such coupling may be made by a pin 65 in suitable holes in a clevis type coupler 67. In some applications, the furnace cleaning apparatus 11, and particularly the scraper portion 17, may be removably mounted on, or made an integral part of, either of the aforementioned cars.

Placement of the furnace cleaning apparatus relative to the converter may be easily and conveniently performed from a remote location, such as the furnace operators pulpit (not shown). It is desirable, however, to position the car 15 so that the scraper teeth 55 are substantially directly below the axis of the trunnion shafts, about which the converter rotates.

The converter may be readily rotated about its horizontal trunnion and the cleaning apparatus 11 may be located and maintained in preselected locations below the vessel to accomplish the cleaning operation. As mentioned previously, the car 15 is located in a first operative position, indicated in FIG. 1, and the converter vessel is angularly disposed for movement in the direction of the arrow A to accomplish a first cleaning operation.

The converter is conventionally oscillatable about its trunnions and thereby about its horizontal axis. The vessel oscillates and the lip of the vessel then engages the teeth of the scraper, whereby the accumulated slag, metal, and other deposited matter is removed from adjacent the mouth of the vessel.

The material removed in this manner falls onto the rubble chute 59, and is directed downwardly toward the usual rubble pit (not shown) located beneath the fur nace vessel. Any such rubble material which may happen to fall between the vertical plates of the arm-like structure 33, passes through a central opening 69 provided in the center of the car 15. Thus, there is no large accumulation of removed matter on the upper deck of the car.

If the accumulated matter adjacent the mouth of the furnace is excessive, and if it is too difficult to remove with one or two oscillatory motions of the furnace, then, it may be necessary to proceed in a slightly different manner. The car 15 may be located in a first position, slightly to the right of the position as viewed in FIG. 1. In such first position, the scraper teeth will engage the vessel, but remove only a small amount of deposited matter. Thereafter, the apparatus 11 may be moved toward the left, to successive other positions and the process repeated until the entire deposited matter is removed.

Those skilled in the art will recognize that removal of the accumulated matter will create severe shock loads on the vessel and the cleaning apparatus. The shock loads, imposed on the teeth and the apparatus, will be absorbed by the resilient spring mounting at the right hand or rearward end of the car. The downward pivotal motion of the scraper structure 17 is resisted by the springs 51, and the upward travel of the scraper 17 is resisted by the stop members 51 engaging the bearing plates 49. The normal, at rest position of the scraper apparatus, however, is with the bearing plates 49 engaging the stop members 51 about as shown in FIG. 1.

The apparatus of the present invention may be maneuvered by the operator of the basic oxygen furnace and the combined operation can be performed with a minimum of labor and auxiliary equipment. The apparatus of the invention, being mobile, may be used for one or more furnaces, and may be conveniently removed to a storage location and kept in readiness for use at any time. The apparatus of the present invention is versatile, more effective, and more efiicient than the present apparatus.

As a result of the essential features and advantages of the present invention, a mobile basic oxygen furnace cleaning apparatus is provided which possesses greater efliciency in use with the furnace vessel and greater consequent economy.

I claim:

1. Apparatus for removing accumulated matter from adjacent the mouth of a furnace vessel rotatable about an axis, comprising:

(a) a car mounted on wheels for location relative to said furnace vessel;

(b) a bar resiliently mounted transversely of said car;

(0) said bar having an arcuate upper edge whose center of curvature is above said bar;

(d) a plurality of scraper teeth mounted to said bar in spaced apart substantially parallel relation, with the upper edges of said teeth substantially parallel to the upper edge of said bar;

(e) means to position said car relative to said furnace vessel whereby, when said vessel is inverted and oscillated above its axis, said teeth engage and remove the accumulated matter from adjacent the mouth of said vessel; and

(f) means to conduct the removed material away from said car.

2. The apparatus of claim 1 wherein:

(a) the resilient mounting of said bar comprises a plurality of springs interposed between said bar and said car whereby the teeth mounted to said bar are urged against said accumulated matter.

3. Apparatus for removing accumulated matter from adjacent the mouth of a furnace vessel rotatable about an axis, comprising:

(a) a car mounted on wheels for location relative to said furnace vessel;

(b) a bar resiliently and pivotally mounted transversely of said car and having an arcuate upper edge with the center of curvature thereof located above said bar;

(c) a plurality of scraper teeth mounted to said bar in spaced apart substantially parallel relation, with the upper edges of said teeth substantially parallel to the upper edge of said bar;

(d) means to position said car relative to said furnace vessel whereby, when said vessel is inverted and oscillated about its axis, said teeth engage and remove the accumulated matter from adjacent the mount of said vessel; and

(e) means to conduct the removed material away from said car.

4. Apparatus for removing accumulated matter from adjacent the mouth of a furnace vessel rotatable about an axis, comprising:

(a) a car mounted on wheels for location relative to said furnace vessel;

(b) a bar resiliently and pivotally mounted transversely of said car and having an arcuate upper edge with the center of curvature thereof located above said bar; and

(c) scraper means mounted on said bar whereby, when said vessel is inverted and oscillated about its axis, said scraper means engages and removes the accumulated matter from adjacent the mouth of said vessel.

5. Apparatus for removing accumulated matter from adjacent the mouth of a furnace vessel pivotable about an axis, comprising:

(a) a mobile unit adapted for movement relative to said furnace vessel;

(b) a support bar pivotally mounted on said unit, said bar being disposed transversely of the unit;

(c) stop means to restrict the pivotal movement of said bar in one direction;

((1) resilient bias means urging said bar against said stop means and resisting pivotal movement of said bar in the opposite direction;

(e) scraper means mounted to said bar with the operative edge of said scraper means touching an are having its center of curvature above said bar; and

(f) means to position said unit relative to said furnace vessel whereby, when said vessel is oscillated, said scraper means engage and remove the accumulated matter from adjacent the mouth of said vessel.

6. The invention set forth in claim 5, wherein:

(a) means is provided to conduct the removed material away from said unit.

7. Apparatus for removing accumulated matter from adjacent the mouth of a furnace vessel pivotable about an axis; comprising:

(a) a mobile unit adapted for movement relative to said furnace vessel;

(b) support means resiliently mounted on said unit;

(c) scraper means mounted to said support means and having an arcuate upper edge with the center of curvature thereof above said scraper means; and

(d) means to position and maintain said unit relative to said furnace vessel whereby, when said vessel is inverted and oscillated about its axis, said scraper means engages and removes the accumulated matter from adjacent the mouth of said vessel.

References Cited UNITED STATES PATENTS 1,144,065 6/1915 Roitzheim et a1 l5l04.1 2,051,569 8/1936 Morrison 15-93 FOREIGN PATENTS 1,266,618 6/1961 France.

CHARLES A. WILLMUTH, Primary Examiner. L. G. MACHLIN, Assistant Examiner. 

1. APPARATUS FOR REMOVING ACCUMULATED MATTER FROM ADJACENT THE MOUTH OF A FURNACE VESSEL ROTATABLE ABOUT AN AXIS, COMPRISING: (A) A CAR MOUNTED ON WHEELS FOR LOCATION RELATIVE TO SAND FURNACE VESSEL; (B) A BAR RESILIENTLY MOUNTED TRANSVERSELY OF SAID CAR; (C) SAID BAR HAVING AN ARCUATE UPPER EDGE WHOSE CENTER OF CURVATURE IS ABOVE SAID BAR; (D) A PLURALITY OF SCRAPER TEETH MOUNTED TO SAID BAR IN SPACED APART SUBSTANTIALLY PARALLEL RELATION, WITH THE UPPER EDGES OF SAID TEETH SUBSTANTIALLY PARALLEL TO THE UPPER EDGE OF SAID BAR; (E) MEANS TO POSITION SAID CAR RELATIVE TO SAID FURNACE VESSEL WHEREBY, WHEN SAID VESSEL IS INVERTED AND OSCILLATED ABOVE ITS AXIS, SAID TEETH ENGAGE AND REMOVE THE ACCUMULATED MATTER FROM ADJACENT THE MOUTH OF SAID VESSEL; AND (F) MEANS TO CONDUCT THE REMOVED MATERIAL AWAY FROM SAID CAR. 